Overturen CAN be a gimmick, but it can also be a very very useful tool, don't give him the wrong impression. As far as finding names with a few hundred type-ins, those still may be good names. Most of the type-ins won't have links on the internet, since it's just a the user who mistypes it and not necessary the website publishers (though this does happen). Gauging it's popularity on links is not a good idea. Remember that type-ins can be typos of another popular site, like leaving a letter off, or making a double letter. Also, it could be the name with a different TLD. It could also be a foreign word, who knows. Search for the key term and see what you find. The general rule is, if you don't know and can't find any reason why that particular type-in would actually be feasible, don't buy. Use overture in conjunction with google and in several different ways, you should be fine.
Joe